Public transit doesn't have to be a total bummer if you've got a nice enough hub for it all to connect to. That seems to be the logic behind the upcoming 1.5-million-square-foot, San Francisco Transbay Transit Center. Some are calling it the city' "Grand Central," and if it lives up to the plans, it'll certainly be grand.

Designed by Cesar Pelli, and his office, Pelli Clarke Pelli, the gorgeous hub is still in its earliest construction phase, but new renderings are giving a peek into its potential awesomeness. The sprawling complex will take up three city blocks on its completion, and stand three stories tall. Its top will feature a 5.4-acre roof park designed by PWP Landscape Architecture, and three enormous skylights that bring some sun down to even the deepest levels of the structure. Mixed in with the greenery, the Transbay Hub will boast a wide variety hangout spaces like cafes, a playground, and even an amphitheater and cycling lanes.

Between the park above and the BART trains below is a wealth of stunning design. The hub's guts are composed of a beautifully simple, white framework and all the enormous windows you could ever hope for. It's certainly a more modern take on the classic transit hot-spots it aims to rival in scope, and the new renderings make it look flat-out futuristic. Trains won't start pulling up until 2017, but in the meantime we can dream of how great it would be if all public transit looked this good. Let's just hope they can manage to keep it looking clean and pristine. [Co.Design]